Improved silicon master tools for hot embossing

This paper focuses on the improvement of micromachined silicon tools by protective coatings which incorporate both low friction/low stiction properties and high hardness values. Such coatings like DLC (ta-C) and TiN are known from tool making and forming in mechanical engineering and will be investigated for micro structured silicon hot embossing tools

Verfahrensgrundlagen zur Herstellung von Oxidschichten fuer optische Anwendungen durch Laser-PVD. Teilvorhaben: Laser-PVD mit gepulsten Laserquellen verschiedener Wellenlaengen Abschlussbericht

The aim of the studies was the deposition of oxide films for use as optical coatings by means of oxygen ion assisted pulsed laser deposition and the investigation of their microstructural and optical properties in dependence of the deposition parameters. An excimer laser operating at 248 nm wavelength and a CO_2-TEA-laser operating at 10.6 #mu#m wavelength was used for the ablation and evaporation, respectively, of sintered Y_2O_3, HfO_2 and ZrO_2 targets as well as amorphous SiO_2 targets. The focused laser beams were scanned in spirals with constant vector velocity across the target surface. Oxygen ion bombardment of the growing films by means of an ion beam produced in an r.f. ion source aimed at the variation of the oxygen content as well as the modification of the structure and optical properties of the films. The structure, stoichiometry and surface morphology as well as the optical properties of the films, such as transmission, reflection, refractive index, absorption coefficient in the visible and ultraviolet wavelength range and the laterally resolved absorption and laser damage thresholds at the Nd:YAG-laser wagvelength of 1.06 #mu#m, were determined and the influence of the deposition parameters on those properties was examined. Both amorphous and polycrystalline films of the yttria, hafnia and zirconia with high packing density and high bulk-like refractive indices were prepared. Moreover, the refractive indices can be varied by the variation of the deposition parameters. The absorption and laser damage thresholds at 1.06 #mu#m wavelength of single films are only partly comparable with those of continuously evaporated films since the films still contain absorbing particulates. The relations between the deposition parameters and the number of those particulates, the absorption and the laser damage thresholds are shown and discussed. On the basis of the variation of the refractive index with only one deposition parameter over a range of 0.3, highly reflecting multilayer systems consisting of alternately high-refractive index and low-refractive index sublayers of only one material were prepared. (orig.)SIGLEAvailable from TIB Hannover: F97B1021+a / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Bildung, Wissenschaft, Forschung und Technologie, Bonn (Germany)DEGerman